Processor-based prior art vending machine controllers (VMCs) typically have been implemented using a low cost, embedded controller, e.g., the Intel brand model 8051. Such a controller separately performs many vending machine control operations, including monitoring, storing, and periodically reporting data pertinent to the operation of the vending machine, e.g., sales and inventory information.
The Cedrone patent (U.S. Pat. No. 4,776,548) discloses a system for monitoring a vending machine and periodically transmitting information relating to machine conditions, sales and product inventory to a central computer.
The Girouard patent (U.S. Pat. No. 4,982,346) discloses an automated system for point-of-sale-type advertising and promotional campaigns, having a computer which can display advertisements on a monitor, manage promotional sweepstakes, display product or store locator maps, dispense coupons, accept orders, manage customer surveys, and communicate with a remote host computer.
The Gorog patent (U.S. Pat. No. 4,947,028) discloses a vending machine that can accept voice commands via a voice recognition system (and communicate with the customer via a voice synthesizer) to accommodate those persons who are unable to perform manual data entry tasks. In addition, the Gorog patent discloses a vending machine that can remotely verify a customer's credit worthiness prior to permitting a sale on credit to the customer.
The Horne patent (U.S. Pat. No. 5,091,713) discloses a vending machine that incorporates a modem 11, a credit card reader 40, a display panel 50, a printer 70 and a speaker 80. The display panel and/or the speaker can be used to present messages and advertising, and the printer can be used to prepare coupons, promotional information, rebate slips and the like.
The Wilder patent (U.S. Pat. No. 5,408,417) discloses a vending machine incorporating a touch screen display panel 11, aural prompts in a plurality of languages, and the ability to accommodate a plurality of payment methods.
The Ostendorf patent (U.S. Pat. No. 5,442,568) discloses an audit/monitoring system for use with a plurality of automated vending machines.
The Brown patent (U.S. Pat. 5,445,295) discloses an automated vending machine that is remotely controlled by a host computer, that can permit a customer to sample the audio/video merchandise, but which has only a single external serial port for external communication.
The Rademacher patent (U.S. Pat. No. 5,450,938) discloses a group of vending machines that interface with a common controller incorporating a money-handling/accrediting device. The money-handling/accrediting device has a reader for encoded cards as well as a coin acceptor, and issues a bonus, or premium, to patrons using encoded cards.
The Cragun patent (U.S. Pat. No. 5,504,675) discloses a neural-network-based vending kiosk that adaptively selects presentation-programs based upon feedback from customers. The feedback represents the relative success of the currently running presentation-programs and is used to select subsequent presentation-programs that are most likely to please the customers present at the kiosk at that moment.
The operating systems of such prior art controllers can be configured to perform the many vending machine functions in a timesharing fashion, though the processor of the VMC operates so slowly that the timesharing is noticed by the parties that are sharing the microprocessor's time, i.e, the timesharing is not transparent.
A practical consequence is that, while a customer conducts a vending operation, the VMC cannot simultaneously provide the sales/inventory information to a remote host over the modem. For the remote host, this becomes problematic because usually there are a great many vending machines from which marketing information must be retrieved. A remote host can expend a great deal of time waiting for VMCs to connect and provide sales/inventory information.
A similar practical consequence is that, if the VMC connects to the remote host and attempts to provide the sales/inventory information over the modem, and if a customer attempts to initiate a vending operation, either the VMC must terminate the connection to the remote host in favor of the vending operation, or the VMC must complete the communication session with the remote host before attending to the vending operation. The latter circumstance might annoy a customer to the point that the customer would retaliate by purchasing a product from an adjacent vending machine or other vendor rather than waiting for the busy vending machine to become available. Alternatively, if a prior art VMC could provide a multimedia marketing program to attract customer attention, and if a customer initiates a product purchase during the multimedia program, then either the multimedia program is abruptly and awkwardly interrupted or the customer has to wait for the multimedia program to finish before the vending operation can proceed.
Some prior art vending machine controllers provide two serial ports, one for a modem to connect to a remote host and one for a local connection, via a cable or by an infrared light link, to a hand-held computer wielded by a person servicing the vending machine, e.g., restocking it. The prior art provides these two serial ports either by manufacturing a custom integrated circuit (IC) having two serial ports integrated on the same silicon chip as the processor or by using two universal asynchronous receiver/transmitter (UART) devices connected to the data bus of the processor.
Using a custom IC is very expensive. In the vending machine industry, the cost of the vending machine controller is approximately 10% of the cost of the vending machine. As such, a controller for a vending machine is an especially price-sensitive component of the vending machine. Consequently, the use of a custom IC is impractical. Similarly, the use of two UART devices imposes additional expense, although not as great as the use of a custom IC.
In the alternative, if the costs associated with two dedicated serial connections could not be tolerated, the prior art is content to require a service person to physically disconnect the modem for the remote host when the service person desired to connect a hand-held computer to the vending machine controller. Having to break and make physical connections is inconvenient for the service person and potentially damaging for the vending machine.
Thus, there is a need in the prior art for a vending machine controller that provides the equivalent performance to two serial ports built on the same silicon chip as the processor without imposing the cost of a custom integrated circuit upon the vending machine controller. In addition, there is a need in the prior art for a vending machine controller that can transparently multi-task, e.g., conduct the transfer of sales information to a remote host over a modem at the same time that it vends a product to a customer.
Non-analogous prior art includes a switching device for connecting multiple personal computers (PCs) to a single printer. The device recognizes when a PC sends a print job, via a parallel connection rather than serial, to the printer and connects the printer to the sending PC for a predetermined amount of time that is sufficient for the print job to be received by the printer, after which the switching device releases the line connecting the PC and the printer. In other words, the connection is terminated on a time-out basis rather than under the control of the receiving device, i.e., the printer.